Doug,
About the aux. battery, the relay under the driver's seat of your
'91 westy is not for a aux. battery.
That relay that you mentioned is for the refrigerator.
It turns the refrigerator on and off, while it's running
on the 12 volt setting, depending on if the alternator is charging or not.
Westfalia only installed the refrig relay in that box for
convenience reasons, because the U.S. campers weren't factory
equipped with aux. battery, and the space was unused anyway.

To install a aux. battery, you should get an additional relay,
similar to the one for the frig., and run an additional wire
from the main battery to the aux. battery.
I wrote a how-to article on this awhile back. It's in the archives
 January 29, 1999 under heading "Re: Flash Alert! Dual Battery Relay".
I think there is a part one with all the parts you need, and a part two,
how to put them together.
Harald
'90 westy
----------
> From: Doug Hornberger <DHornberg@AOL.COM>
> To: vanagon@GERRY.VANAGON.COM
> Subject: Awnings, propane heaters and auxillary batteries
> Date: Sunday, April 23, 2000 11:33 AM
>
> Hello Everyone,
> I own a 1991 Westfalia Vanagon and am interested in adding a few
additions. I
> am looking for any recommendations/suggestions on what the best propane
> heaters, auxiliary batteries (I do have the box and relay under the
drivers
> seat), and awnings are for a 91 Vanagon. I would also be interested in
any
> recommendations of where I can purchase these items, and who might be
able to
> install them in the New Jersey, Eastern PA, or Western NY area.
> Thank you for your help on this.